Default GraphQL response is now HTTP 500 (graphql.org)

GraphQL is changing its default HTTP behavior from returning 200 OK to returning HTTP 500 for all responses, effective with the October 2026 spec release. The post argues this makes monitoring and alerting work reliably when GraphQL returns partial data alongside errors. It keeps the existing `errors` structure and introduces an optional `everything_is_fine` boolean for clients that want a simple indicator of whether returned data is usable.